WASHINGTON — Donald Trump’s campaign is making its biggest general election ad buy to date, with plans to spend upward of $10 million on commercials airing over the next week or so.

The campaign is expecting to air a new ad, which paints rival Hillary Clinton as a job-killer, as soon as Monday in nine states: Ohio, Pennsylvania, North Carolina and Florida, where the campaign has already been on the air, along with New Hampshire, Virginia, Iowa, Colorado and Nevada — all battleground states.

Trump, the Republican presidential nominee, has so far been badly outspent by his Democratic rival and groups supporting her. Since clinching her party’s nomination in early June, Clinton has spent more than $77 million on television and radio advertising, largely targeting voters in battleground states, according to Kantar Media’s political ad tracker.

Trump finally hit the airwaves earlier this month with an ad focused on immigration, and so far has only spent about $5 million.

Clinton has reserved about $9.2 million in airtime this week.

The new investment comes amid signs the campaign sees that Trump’s lagging poll numbers may be improving against Clinton’s following a campaign reboot.

Trump senior communications adviser Jason Miller said in a statement that the billionaire businessman’s “positive message of economic opportunity is working and we see the national and battleground state polls all moving in the right direction.”

“With Hillary Clinton off the campaign trail yet again this week and continuing to take many communities’ votes for granted, we see this as the right time to show voters the benefits of an American economy under the leadership of Mr. Trump,” he added.

Clinton will be spending much of the week in private fundraisers in the Hamptons, the wealthy enclaves of eastern Long Island, New York.

Trump is also expected to unveil on Monday his second ad of the general election. It will focus on his economic message, contrasting his approach with Clinton’s.

“In Hillary Clinton’s America, the middle class get crushed. Spending goes up, taxes go up. Hundreds of thousands of jobs disappear. It’s more of the same, but worse,” says a narrator.

The narrator continues that, in “Donald Trump’s America, working families get tax relief. Millions of new jobs created, wages go up. Small businesses thrive.”

In fact, neither Trump nor Clinton’s tax plans would have any major impact on how much the middle class pays, analysts say.